Generator regulator



Dec. 21, 1943. w. J, RADY' GENERATOR REGULATOR Filed April 10, l942 5 Sheets-Sheet l 4.. 2 g w f 2 \l 7. 4 I J 2 r M2 L M T r 2 r u C cur our an INVENTOR William J Rudy WWW-fix QJATToR-NEYS Dec. 21, 1943. w. J. RADY GENERATOR REGULATOR Filed April 10, 1942 5 Sheets-Sheet 3 lN VENTOR Wi/l/am J fiaay $6M 1 ATTORNEYS JEN Dec. 21, 1943. w. J. RADY GENERATOR REGULATOR I III INVENTOR M'l/iam J Pady Y 5 Sheets-Sheet 4 Filed April 10, 1942 M Mvfib a ATTORNEYS Dec. 21, 1943. w, J RADY 2,337,494

GENERATOR REGULATOR Filed April 10, 1942 5 Sheets-Sheet s if WZ-Z'ZZ Ed L ATTORNEYS Patented Dec. at. rate can as; PATENT oFFIcE 2.337.494 GENERATOR. REGULATOR William J. Rady, Anderson, Incl, assignor to Gen-- eral Motors Corporation, Detroit,-Mich., a corporation of Delaware Application April 10, 1942, Serial No. 438,477

Claims.

This invention relates to a storage battery charging system including an electric generator which is regulated by a vibratory regulator.

It is an. objectof the present invention to provide a system of generator voltage regulation through the use of vibratory regulators which are simple in construction and are reliable and durable in operation and which readily lend themselves to shielding to eliminate interference with radio apparatus.

. This invention is particularly concerned with the regulation of generators used on military air and'land vehicles. These generators haverelatively large capacity and consequently the field current is relatively high. .In carrying outthe objects of my invention in connection with such generators, I provide a plurality of field circuits in order to divide the total field current. Each field circuit is provided with a vibratory regulator,-

the vibrators of which are controlled by a master I merits can readily be efiiected.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompany'ing drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. l is a wiring diagram of a generator regulating system embodying the present invention and shows particularly the arrangement of the minals with which. the generator and battery leads are connected.

Fig. 2 is a simplified diagram of. the circuit shown in Fig. 1.

Fig. 3 is a wiring diagram of a modified form of the invention and shows the arrangement of the vibrator. terminals and the instrument panel terminals. 1

Fig 4 is a simplified diagram of shown in Fig. Fig. 5 is a front elevation of an instrument panel andjunction bot z supporting the field vibrators and the master vibrator shown diagrammatically in first four figures.

the circuit Fig. 6 is a; side view looking in the direction of arrow 6 of Fig.5.

Fig. 7 is a bottom view looklng in' the direction of the arrow 1 of Fig. 5.

Fig. 8 is a fragmentary back view of the June I tion box looking in the direction of'arrow 8. of

Fig. 6 with the back or mounting plate removed to show the sockets which receive the plugs from the master vibrator and one of the field vibrators.

Fig. 9 is a sectional view of the line 9-9 of Fig. 8. I Fig. 10 is a sectional view on line l0--l0'of Fig. 9.

Fig. 11 is a view in the direction oithearrow ll of Fig. 10, the vibrator case and base being shown in section.

line lZ-IZ of Fig. 10.

Fig. 12 is a sectional view or the vibrator or;

Fig. 13 'is a fragmentary view on line l3-l of Fig. 11.- v

Fig. 14 shows an assembly of the fieldregulatlng resistances; the base upon which the resistance assemblyis mounted is shown in'section;

and an end position of the assembly is shown in section to show how the assembly upon a supporting screw.

Fig. 15 is a wiring diagram of another form oi.

is mounted the invention in which a master current resu lator, as well as a master voltage regulator controls the field vibratory regulators.

Referring to Fig. 1.9. generator 20 is provided with field circuits 2|, 22 and 23 connected re spectively with terminals Fl F2 and F3 of the regulator assembly and by wire 24 with generator positive brush'25 connected by wire 26 and cutout relay 2'! with the positive terminal of battery 28.

29' and with assembly.

The regulator assembly includes an instrument panel and junction box represented by the dot dash rectangle 40 in Fig. 1. the terminals'G+, G, Fl, F2, and and field regulating resistances R l, R2 and R3 connected as shown between terminal G- and terminals Fl, F2, and F3 respectively. The box 40 supports a master vibrator MV and threefield regulating vibrators FVl, FVZ and FV3. 'All of these vibrators have plug terminals engaginglsockts' can. ried by the box All. The sockets'for vibrator MV are marked Ma; Mb, Me and Md. The sockets The negative terminal battery 28 is connected by wire 29 with generator negative brush L Positive brush 25-is connected bywires lit a 'and 34- with terminal G+ 0f the regulator assem- -vibrator terminals and the instrument panel tern. brush 30 s connected by wiresterminal G- of the regulator Thebox til supports v brate.

for-vibrator FVl are marked la, lb, l and Id. The sockets for vibrator FVZ are marked 2a, 2b, 2c and 2d. The sockets for vibrator FV3 are marked Sea-3b, 3c andBd. Socket Ma and sockcts id, 2d and 3d are connected as shown with terminal (3+. Socket Md is connected with terminal G. The sockets Mc, lc, 2c and 3c are connected together. The sockets Mb, lb, 2b and 3b are connected. The sockets la, 2a and 3a are connected respectviely with terminals Fl, F2

. and F3.

Each o'iihe. four vibrators has a magnetizable I frame *iil supporting a magnetizable core. 11' and .connectc'd'by a spring-hinge 12 with a magnetiz: able armatin'e 13' supporting a flexible metal lade M carrying a movable contact engageable web a stationary contact. The master vibrator has a pair of normally closed contacts Mk; and

the field vibrators have pairs of normally closed contacts marked respectively llc, 2k and 37a. The

core of each of the vibrators is surrounded by l two coils. In the case of the master vibrator MV thosecoils are assisting and they are marked respectively M2 and M7. The coils of each of the field vibrators are bucking as indicated by arrows LE and y in Fig. '2 and they are marked Ii and l7, 2:" and2j, 3i and 39', respectively. The conneclions between the coils and the contacts of the vibrators and the vibrator sockets are clearlyshown on the diagram and require no further respectively which control the current in fields 21,

22 and 23 respectively, When the voltage of the generator attains that for which the master vibrator MV is adjusted to vibrate, thecontacts Mic open, to open-circuit the vibrator coils i312 and 37'. Coils li,.2i and '32 are then unopposed and are cff ective'to cause the opening of'field.vi--

brator contacts lie, 27:, tile, and thus reduce the field current to cause the generator voltage to decrease, whereupon the master rotor contacts close again and the cycle is re ted so long as the generator voltage tends to exceed the voltage for, which the master vibrator is set to Electrical. check valves iii. and 33 of the copper oxide electrolytic type, shunting the fields 2i, 22 and 23 respectlvelvprev nt the self-induced voltage in these field windings from causing sparking at the contacts of the field vibrators.

In the system shown in Figs. 3 and 4, each field vibrator has asingle coil marked W2-,2I L,3h l'85p6c 'tively. Master vibrator coil Mi (3500 turns of relatively fine wire) is connected with terminal Ma and withcoil Myiof 300'turns of relatively coarse wire and having very low resistanceland with contacts Mk. Normally closed contacts Mk are connected through the frame ill with the junction of coils M1 and M7 and are connected with terminal Mb connected with the b terminals of the field vibrators. Coil M7 is connected with terrnirm'l Mc connected with the c terminals of the fiel dvibrators and with-terminal The a. terminals of the field vibrators are connected rcspcctivelywith the terminals Fl, F2. andFB as in Figs. 1 and 2. Resistance Mr (100 ohms) is connected between terminals Ma and Mb.

While contacts Mk are closed; the generator terminal (3+ and G- are connected by two circuits, coil My being in common to the two circuits.

One of these circuits comprises resistance Mr,

contacts Mic and coil Mj. Since coil My' has very low resistance, resistance element Mr is relied on to provide sufficient resistance between the ter-* minals (3+ and G to prevent short-circuiting ofthe generator while contacts Mic are closed. While contacts Mk are closed ver little current passes through field vibrator coils l h, 2h, Sn and the field'vibrator contacts remain closed; and the resistances R1. R2, R3 remain short circuited. The other circuit across terminals (3+ and G- comprises coils M1 and My which are in assisting relation. Coil My receives the current which passes across contacts Mic plus the current which passes through coil When the generator voltage attains a value such that. the combinedexcitation of coils Mi and My causes the armature I3 of vibrator Mo to be attracted toward its core H, contacts Mic are separated thereby causing the field vibrator l coils lb, 272, (iii to receive current sufficient to to reduce the excitation of the generator.

' caused to increase. This cycle is repeated so long as the voltage of generator tends to attain the value for which the master vibrator MV is set to vibrate. The action of vibrator MV is caused to be more rapid by the opening of contacts Mk whichcauses a reduction of current in coil M9 in addition to that reduction of current which takes place when the current in coil Mi is reduced.

Contacts MR: and coil My provide a low resistance bypass around the coils lh, 2h, 3h when the contacts Mk are closed. Thus the current flow to the coils l'h, 2h, 3h is kept below operating value so long as the master vibrator contacts Mic-remain closed. Resistance Mr prevents a dead short across the line when contacts M7; are closed.

Referring to Figs. 5, 6 and '7, the front face H of case 46 provides an instrument panel upon which vibrators MV, FVi, FVZ and FV3 are mounted in a-manner to be described more fully later on. Upon the inner side of the wall ii are mounted the various terminals G+, (3-, Fl, F2 and F3 and the sockets of the various vibrator terminals. Some of these vibrator terminal sockets are shown in Fig. 8,'narnely the sockets'for the terminals for the master vibratorand the field vibrator FVES, when constructed and wired according to Figs. '1 and 2. Each socket is pro- 'vided by a member 42 integral with a plate 42a and having resilient ears 42b, The plate 42a is located between an insulator 43 and a washer nectingthese terminals with the generator are or the right thereof,

bottom wall 4m in the same manner.

fThe mec'hanica1-. construction* of the master vibrator and the field. vibrators isthe same.

'q out ough an opening at 46, FigJ-e,

within a collar 41 to which a cable may be attached. After the connections within 'thebox have been completed, 'a back plate 48 is assembled and is attached by screws 48a. The back 48 has flanges 48?) supporting soft rubber grommets 480 through which screws may be passed for securing theback 48 to a suitable Support." The bottom wall of the box 40 supports a "housing 49 secured by screws 49a." Housing 49 encloses a resistance assembly 50 which will now be dc:- scribed. 1

In Fig. 14 resistance assembly 50 comprises the resistances RI, R2 and-R3 mounted on insulators I, 52 and 53 provided'at each end with metal eyelets 54 to which the ends of 'a resistance are respectively attached. A supporting screw 55 passes through a metal washer 56 and through an insulating tube 51. Insulating tube 51 passes through the following elements reading from bottom to top in Fig. 14: insulating washer 58, a first eyelet 54, a first terminal clip 59; a second 3 agrarn. shown in Fig; 1, namely the frame "I0 is connected with terminal plugP3a, the outer end of the coil 39' is connectedwith terminal plug P3b. The inner ends'of the coils 37' and'3i and the extension 79a (Fig. Ill-"of bracket I9 are connected with terminal plug P3c'. "The outer end-of coil 3z'is connected with terminal plug P 3d.: The vibrator'is enclosed by a cup-shaped shell "I'00providing-an annular'fshoulder at IOI for receiving the assembly of discs 9|, '92 and I5.

The annular'edge of the housing I00 is formed at I02 so as to clamp the discs 9|, 92 and I5 against the annular shoulder'IOI thereby compressing the periphery portion of thesoft rubber disc 92 to cause the same to be squeezed against theadjacent cylindrical wallof the housing I00, thereby providing an effective seal. Flange I02 is'soldered at .I02a to the metal disc .9I. [The upper end wall of the housing'is provided with a flanged aperture I05 provided by atlange I06 1 providing means for attaching acouplinglconinsulating washer 58, a second eyelet 54, a second terminal clip 59, a thirdinsulatingwasher fieg a third eyelet 54, a" third terminal; washer 60 an'd an insu'latingwash screw 55 passes '-also through a lock a nut 3 threaded thereon, a hole in 'the lbottom ,wall 4L3 of the box 41 L411.v lock washerjk anut '65 threaded on theinner' end of screa .-'55. The leftend portions" of ltheresistance assembly are. j --sec1ired together inthe' same manner and-to th They may differ with respect tojwindings upon their cores II. The construction of thevibrator FV3-will now be described. 5

Withreference to Figs.9 through 13, the lower end portion I la (Fig. 12;) of its core II serves as a rivet for attach g core- II and the frame I0 to a non-conduc material. Th ioore: I--. supports the windings 3i and 37' (Figs; 1 and 2) and abracket I6 havin a screw thread apertured ear 11 for receiving a screw 18, Fig. 11, which attaches a contact brack-' et "I9 carrying the upper contact 80 of the pair of vibrator contacts 3k. The lower contact 8| is mounted on the spring blade 14. The armature l3 and the flexible hinge plate I2 have been referred to in connection with Fig. 1. The parts nected with a tube, not shown, formaking connection with a vacuum pumpQor with a source of inertgas" under pressure. The pr cedure is to evacuate the' housing I00 and admitan inert gas suchas, nitrogen and then evacuate again and fill with nitrogen at a desired pressure. 'The vibrator per se is describedand claimed in my copendin'g applicationSerial- No. 426,1 54 filed JamIaryQ, 1942. l Theiront wall4liof' the 130x40 is provided with holes II0 which will registerwith "th -vibrator connector.p1ugs P3a-, etc a'nd are, of

plate 15 hr sheet, insulating larger diameterthan the-Walls I II of these fpl gs'.

The plugs extend through holes in insulator"43a which is located between 'wall'4 I andfthe insue lator 43 a d serves to insulate therivetfhe as from wall4 (as shown in Fig. 9. L If the system according to Figs. Sand 4 is used 7 the box 40will carry: the plug sockets, terminals and interconnectors shown diagrammatically in Fig. 3 in'place of'thos'e shown in Fig. 1.

- Fig. l5'shows diagrammatically the" combina tion of the system shown in--Figs. 3 and! with .a master current-vibrator MC. The connector between terminalMb and contacts Mk of Figs.

12, I3 and 14 are secured together by rivets 82;"

The hinge I2 is bifurcated and is secured by rivets 83 to the ears 84 of the frame I0. The rivets '82 serve also to attach a plate "85 having a tail 86 providing a hook 81 to which one end:

of a spring 88 is attached, the other end being attached to a hook 89a provided by bracket 89 attached-to frame "I0 by' rivets integral there with. Bending thehooks 8"! and-89a adjusts the tension of spring 88.

The vibratorh'as four terminals 3a, 3b, 3c and 3d as has been described with reference to Fig. 1. These four terminals are provided by plugs which are marked P3a, P3b, P3c and'P3d in Figs. 8, 9, 10, 11' and 12. Each plug terminal provides a rivet portion for securing together the following superposed elements readingfrom bottom to top in Fig. 12: an insulating disc 90, a metal disc 9|, 9. soft rubber disc 92 and the insulating disc I5.

The soft rubber disc was vulcanized'to the metal disc SI and to the. shanks of rivets provided-by the plug terminals are made according to-the di- 3 and 4 is replaced by a series of connections between terminals MbI, M122; Mb3; Mb4 in-Fig. 15. The contacts MCIc of master current vibrator MC are connected bEIZWBGI'iMbZ and Mb3'." The magnet coil MCh of the master-current vibrator MC isconnected with terminals I I5 and l I6 connected,=respec tively, with terminal G+ and ter'-. minal I2I of reverse-current relay I20 having a series or current coil I23-connected be.tween.terminalsIZI and I24 andvoltagecoil I22 connected between terminal HI and ground, Th ew armature (not shown) of relay I20 carries contacts I26 and I28 separated by insulation I29- Contact I26, which is connected byfiexible lead I30 with grounded terminal, I3I..normally engages contact I25 connected 'with' contact I21 adapted to" .be engaged by'armature; supported contact I28 but normally not engaged by it. Contaflc't IZB is connected with terminal I24. Contact I21 is connected 'withterminal I32 connected by wire I33 with terminal I43'of cut-out relay I35. I The cutout relay; I35, which is controlled by the reverse current rela I20, has a terminal [341 connected; with terminal I 2.4- of relay .I :0. Relay is connected with terminal I31a connected with terminal B+ connected with battery 28. Strap I38 carries a terminal clip I45 connected by wire I46 with terminal Ma of master voltage regulator MV. Clip I45 is connected by a wire I41 with the junction magnet coils HI and I42 of relay I 35. The magnet coil I of relatively few turns (800 turns) and low resistance is connected with terminal I43. The magnet coil I42 of relatively high resistance (6800 turns of #34 wire) is connected with a terminal I44 which is grounded.

The electrical dimensions of'the coils of the master vibrator MV and of the-field vibrators FVI, FVZ, FV3 and of the resistance Mr would be the same as for Figs. 3 and 4 other conditions being the same. The normal by-pass around the field vibrator coils Ih, 2h, 3h is provided by the circuit comprising, in series, master current vibrator contacts MCk, master voltage vibrator contacts Mk and coil M7, This by-pass is opencircuited whenever either or both of these sets of contacts open as the result of either the attainment of a predetermined generator voltage the attainment of a predetermined current output or the attainment of both. Then the fieldvibrators become efiective to reduce fullexcitation as has been explained with reference to Figs. 3 and 4.

The master vibrators MV and MC do not function until after relay I20 causes relay I35 to complete the battery charging circuit indicated in heavy lines in Fig. 15. At a certain generator voltage in excess of battery counter voltage, coil I22 of relay I20 is excited sufiiciently to cause the armature (not shown) to move to cause contact I28 to engage contact I21 and contact I28 to separate from contact I25. Then terminal I24 is connected by contacts I21 and I28, terminal ,I32, wire I33, terminal I43 with coils HI and I42 which are ground-connected with the generator 20. Under these conditions coil I4I assists coil I42 in closing the contacts of relay I35. The battery charging circuit is completed by the engagement of contacts I31 and I40 with contacts I38 and I39respective1y, connected by strap I38. Coil MCh of master current regulator MC becomes operative and coils Mi and M1" of master voltage vibrator MV are connected directly across the line. Coil I42 is also connected directly across the line by the closing of the contacts of relay relay I35. The operating position of the armature of relay I20 must be fully established before relay I35 closes, and the armature of relay I20 must fully return to normal position before relay I35 opens.

The space enclosedby parallel dot-dash lines represents an instrument panel or junction ,box'

40a upon which each of the instruments F'VI, FV2, FV3, MC, MV, I20, I35 may be separately mounted by any suitable means including plug and socket terminals such as illustrated in Fig. 8. For the terminals in the battery, charging circuit (heavy lines) screw iastenings are recommended.

The box 40a carries the field terminals FI, F2, F3, a generator terminal (3+ and a battery terminal B+. lithe system shown in Fig. were a non-grounded system, a metallic part of the box 40:: would serve as a common ground for the grounds indicated in Fig. 15, and this'metallic part would carry a G terminal to which the generator and battery are connected as in Fig. 3.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it i to be understood that other forms might" be adopted all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A battery charging system comprising in combination; a storage battery; 2. battery charging generator having a plurality of field circuits; an electrical valve connected across each field circuit; a resistance unit in each field circuit; circuits each'including a normally closed switch shunting a field resistance; electromagnets having cores and coils for opening the resistancetromagnets of a magnetism suflicient to effect the opening of the resistance shunting switches said circuit including normally closed contacts; and

electro-magnetic means responsive to a predeter- I35. Coil I42 is therefore energized by a circuit independent of the relay I20, so that any fluttering of the armature of relay I does not effect relay I35. The master vibrators MV and MC are operative individually and jointly. to control the field vibrators FVI,'FV2, FV3 in themanner accomplished by the vibrator MV alone in Figs 3 and 4,

When the speed of the generator 20 falls to such low value that the battery 28 tends to discharge through the generator 20, the current in coil I23 of relay I20 reverses thereby ngutralizing the effect of .the coil I22 and the armature of relay I20 is returned by a spring (not shown) to normal position in which contact I28 reengages contact I and contact I28 separates from contact I21. When this occurs, the coil I4I of relay I is connected in bucking relation to the coil I4;2 of relay I35; coil I42 is neutralized and relay I35 opens. Any fluttering of the armature of relay I20 between the operating position of engaging contacts I21 and I28 and of separating contact I26 from contact I25 and the normal position shown in Fig. 15 does not affect mined generator voltage for opening said last mentioned normally closed contacts.

2. A battery charging system comprising in combination; a storage battery; a battery charging generator having a plurality of field circuits; an electrical valve connected across each field circuit; a resistance unit in each field circuit; circuits each including a normally closed switch shunting a field resistance; electromagnets having cores and coils for opening the stanceshunting switches; a circuit including coil bucking said electromagnet coils and normally opera tive to neutralize the effect of said electromagnet coils so as to prevent the creation in the cores of said electromagnets of a magnetism suflicient to effect the opening of the resistance shunting switches said circuit including normally closed contacts; and electromagnetic means responsive to a predetermined generator voltage for opening said last mentioned normally closed contacts.

3. A battery charging system comprising in combination; a storage battery; a battery chargan electrical valve connected across each field circuit; a resistance unit in each field circuit; circuits each including a normally closed switch shunting a field resistance; electromagnets having cores and coils for opening the resistanceshunting switches; a circuit normall operative to provide a low resistance by-pass around the coils of said electromagnet to prevent the creation in the cores of said electromagnets of a magnetism suillclcntly to eifect the opening of the resistance shunting switches said circuit including normally closed contacts; and electromagnetic means responsive to a predetermined generator voltage for opening said last mentioned normally closed contacts.

4. A battery charging system comprising in combination; a storage battery; 2. battery charging generator having a pluralit of field circuits; an electrical valve connected across each field circuit; a. resistance unit in each field circuit; circuits each including a normally closed switch shunting a field resistance; electromagnets having cores and coils for opening the resistanceshunting switches; a circuit normally operative to prevent the creation in thecores of said electromagnet of a magnetism sufiicient to effect the opening of the resistance shunting switches said circuit including two pairs of normally closed contacts in series; electromagnetic means responsive to a predetermined generator voltage for opening one of said pairs of contacts; and means respon ive to a predetermined generator current for opening the other of said pairs of contacts.

5. A battery char in svstem COITlDlising in combinat on; a storage batte y: a batt ry charging generator hav ng a plurality of field circuits: an electrical valve connected across each fie d circuit: .a res stance unit in ea h field circu t: circui s each including a norma ly closed switch shunting a field res s ance: electromagnets having co es and coils for'opening t e res stance: shunt n switc es: a. c rcu t nor ally o e a i e to provide a low res tance bv-nass a ound the co ls of said ele tromavn ts to r vent the creation in the c res of sai el troma-Qn i's o a magnet sm snfii i ni'. to e ct t e. o n g o the resistance s unting switches said circuit including two pa rs of n rmailv closed c ntacts in series: electroma net c means responsive to a predetermined gene ator vol a e for open n one 01' said pairs of conta ts: and m a s re p nsive to a redeterm ned enerat r the other of said pairs of contacts.

6. A battery c arging system com risin in combination, a. store we hatte v: a hatterv charg ing generator; a first line for conn cting one terminal of the enerator w th a battery t minal of l ke noiariiv and includ ng Current respons ve magnet co l and a no ma ivonen sw tch: a sec nd l ne of opp s te polarity for connecting the other terminal of the generator with the other terminal of the battery. said second line bein for example. a round l ne: a cut-out-relav including the normally open switch of they first line and electromagnetic means for controlling said switch and comprising two magnet coils respectively of low and high resistance connected to a common junction, the otherend of the high resistance coil being directly connected to the second line, said cut-out-relay having means responsive to the closing of the normally open switch for connecting the junction of the two magnet coils with the first line; and a reverse current relay comprising the magnet coil in the first line and a voltage responsive magnet coil across the lines, and a switch means operating in its normal position to connect the low resistance coil of the cut-out-relay with the second line, and actuated by energization of the voltage responsive coil to interrupt the connection between the low resistance coil of the cut-out-relay and the second line and to connect the two coils of the cut-out-relay in series across the lines in assisting relation, said coils being in bucking relation only when the current for opening switch of the reverse-current-relay returns to normal relation while the switch of the cut-outrelay is closed, whereby said last mentioned switch opens.

7. A battery charging system comprising, in combination, a storage battery; a battery charging generator; having a field circuit; a resistance unit in the field circuit; a normally closed switch shunting the resistance; a first line for connecting one terminal of the generator with a battery terminal of like polarity and including current responsive magnet coil and a normally open switch; a second line of opposite polarity for connecting the other terminal of the generator with the other terminal of the battery, said second line being, for example, a ground line; means for controlling the operation of the field-resistance shunting-switch and including electro-magnet windings, a cut-out-relay including the normally open switch of the first line and electromagnetic means for controlling said switch and comprising two magnet coils respectively of low and high resistance connected to a common junction, the other end of the high resistance coil being directly connected to the second line, said cut-out-relay having means responsive to the closing of the normally openswitch for connecting the junction of the two magnet coils with the first line; and responsive to the closing of the normally open switch for connecting across the lines the electromagnet-windings which control the operation of the field-resistance shunting switch; and a reverse current relay comprising the magnet coil in the first line and a voltage responsive magnet coil across the lines, and a switch means operating in its normal position to connect the low resistance coil of the cut-out relay-with the second line, and actuated by energization of the voltage responsive coil to interrupt the connection between the low resistance coil of the cut-out-relay and the second line, and to connect the .two coils of the cut-out-relay in series across the-lines in assist ng relation, said coils being in bucking relation only when the switch of the reverse-current-relay returns to normal relation while the switch of the cut-outrelay is closed, whereby said last mentioned switch opens.

8. A battery charging system comprising, in

, combination, a storage battery; a battery charging generator; having a plurality of field circuits; a resistance unit in each field circuit; electromagnetically operated field relays each having a, normally closed switch shunting a field resistance; a first line for connecting one terminal of the generator with a battery terminal of like polarity and including current responsive magnet coil and a normally open switch; a second line of opposite polarity for connecting the other terminal of the generator with the other terminal of the battery, said second line being, for example, a. ground line; a master vibrator for controlling the operation of the field relay electromagnets and having electromagnet windings; a cut-out-relay including the normally open switch of the first line and electromagnetic means for controlling said switch and comprising two magnet coils respectively of low and high resistance connected to a common junction, the other end of the high resistance coil being directly connected to the second line, said cut-out-relay having means responsive to the closing of the normally open switch for connecting the junction of the. two magnet coils with the first line; and responsive to the closing of the normally open switch for. connecting across the lines the electromagnet windings of the master vibrator; and

a reverse current. relay comprising the magnet coil in the first line-and a voltage'responsive magvnet coil across the lines, and a switch means operating in itsnormal position toconnect the low resistance coil of the cut-out-relay with thesecond line, and actuated by energization of; the voltage responsive coil" tolinterrupt the. connection betweenv the low resistance coil of the cutout-relay'andzth'e second line and. to connect the two: coils of the. cut-out -relay in series across the lines inxassisting relation, said coils being in buck= ing relationonly when the switch oithe reversecurrent relay returns to normal relation while.

magnet coilland a. normally'open switch; a. secnd. line-of! opposite polarity for connecting the;

other terminal of the" generator. with the other terminal ofthe battery, said second linebeing,

for example, a ground; line; a master vibrator for controlling theoperation of the fieldrelay electromagnets and having a pair of normally closedcontacts for; shunting the field-relay electromagnets and havingrelectromagnetwindings for controlling the last mentioned contacts; a resistor connected across'the. lines through said last mentioned contacts-to protect the generator; a cut-out-relay including the normally open switch of the first: line and electromagnetic means for'controlling: said switch and comprising. two magnet coils respectively of low and high resistance connected to a common junction, the other-end of. the high resistance coil being directly connected. to the second line, said. cut-outrelay havingimeans responsive to the closingot the normally open switch. for connecting" the Junction of the two magnet coils with: the first line; and responsive to the'closing of. the normally open switch for connecting across the lines the electromagnet windings of the master" vibrator; and a reverse current relay comprising;

the magnet coil in the first line and a voltage. responsive magnet coil across the lines, and. a switch means operating in its normal positionto connect the low resistance coil of the. cut-outrelay with the secondline, and actuated by ener- 'gization of the voltage responsive coil to interrupt the connection. between the low resistance coil of the cut-out-relay'andthexsecond.lineand to connect the two coils of the cut-out-relay in series across the lines in assisting relation, said coils being in bucking relation only when the switch of the reverse-current relay returns to normal relation while the switch of the cut-outrelay is closed. whereby said last mentioned switch opens.

10. A battery charging system comprising, in combination a storage battery; a battery charging generator; having a plurality of field circuits, a resistance unit in each field circuit; electromagnetically operated field relays each having a normally closed switch shunting a field resistance; a first line for connecting one terminal of the generator with a battery terminal of like polarity and including current responsive magnet coil and a normally open switch; a second line of. opposite polarity for connecting the other terminal of the generator with the other terminal of the battery, said second line being, for example, a ground line; a circuit for by-passing the magnet coils of the field relays and comprising two normally closed switches in series; a resistor connected across the line through said series-connectednormally closed switches; a current" responsive electromagnet for opening one of 3 other end of the high resistance coil being directly connected to thesecond line, said cut-out-relay having means responsive to the closing of the normallycpen switch for connecting the junction of the two magnet coils with the first line; and responsive to the closing of the normally open switch for connecting across the lines the voltage responsive electromagnet which controls the opening of one of said by-passing switches; and areverse current relay comprising themage net coil in the first line and a voltage responsive magnet coil across the lines, and a switch means operating in its normal position to connect the low resistance coil of the cut-out-relay with the second line, and actuated by energization of the voltage. responsive coil to interrupt the connection. between the low resistance coil of the cutout-relay and the second line and to connect the two coils of the cut-out-relay in series across the lines in assisting relation, said coils being in bucking relation only when the switch of the reverse current relay returns to normal relation while the switch of the cut-out-relay is closed, whereby said last mentioned switch opens.

WILLIAM J. RADY. 

